Detachable balloons are used for a wide variety of medical procedures where occlusion of a vessel or duct, or compression at a target tissue site is desired. One specific example is in the treatment of urinary incontinence. In patients suffering from this condition, detachable balloons have been used to successfully treat the bladder sphincter deficiency. One or more detachable balloons are implanted into the tissue adjacent to the neck of the bladder of a patient. The inflated balloons aid in the ability of the bladder sphincter muscles to occlude, which improves or resolves the condition. This method of treatment is preferred as it is minimally-invasive, safe and less traumatic to the patient. As such, various systems have been developed for the delivery of balloon catheters to a desired target site. See, for example, U.S. Pat. No. 5,411,475; U.S. Pat. No. 4,802,479; and U.S. Pat. No. 4,686,962.
Haber et al., U.S. Pat. No. 4,832,680 describe an apparatus and a non-surgical method for treatment of urinary incontinence. The method entails use of a hypodermic needle to implant a balloon in the tissue adjacent to the urethra. Specialized instrumentation is required to aid in positioning the balloon and protecting the balloon during insertion into the patient's tissue. A particular disadvantage in this system is that it is cumbersome and difficult to maneuver and requires complicated instrumentation for protection of the balloon during delivery. As a result, more simple and effective balloon delivery systems have been developed.
An example of such a device may be found in U.S. Pat. No. 5,830,228, which describe a system for delivering a detachable, inflatable balloon at a target site. The system includes a holder, a protective sheath configured for insertion through the holder and a hub at the proximal end of the sheath; a delivery device for carrying a balloon; and a retractor located on the delivery device for withdrawing the sheath. The retractor includes a head which withdraws the hub of the sheath by movement of the head. Use of the system requires insertion of the protective sheath through the holder and retraction of the sheath by rotating the head of the retractor which is located on the delivery device. Internal threads within the head aid in withdrawing the sheath by engaging in external threads on the hub of the sheath.
The above-described delivery systems (and other similar devices not specifically described) offer advantages, including effectiveness and safety to both the user and the patient. However, it has been discovered that an obstacle or disadvantage to such devices is the requirement for specialized instrumentation or that their use is complicated. Additionally, even with the more simple delivery system, the susceptibility of separation of certain component parts, such as the catheter and/or the positioning element, from the delivery system during use in the patient result in major limitations to the reliability of the system. Further, the motion required for retraction of the sheath to expose the balloon is a difficult and more cumbersome motion to perform. Yet still further, the rotational movement necessary to remove the needle (or positioning element) is likely to cause undesirable tissue trauma.
In view of the above, it is apparent that there is a need to provide a delivery system with a more reliable and stable delivery of inflatable, detachable balloons. There is also a need to provide a delivery system that is efficient, simpler to use for the physician and easy to implement. A reliable and efficient delivery system would reduce the overall procedure time required and therefore reduce patient discomfort. Such delivery systems include properties that reduce the amount of effort required by the physician prior to and during use of the system as well as properties that ensure the system remain intact during insertion into the target tissue and during inflation of the balloon.